1. Field of the Invention
This invention relates to an apparatus and process for delivering a pulsed fluid jet that can be used to extinguish a fire, launch a projectile and/or perform other useful work.
2. Description of Prior Art
It is a well known fact that rapidly extinguishing uncontrolled fires can be a very difficult task due to the complex nature of present day fires and the associated urgency of saving lives or minimizing economic loss and environmental damage. Many different types of fire occur today because of a presence of many man-made materials that combust with unusual characteristics and extinguishing such fire rapidly requires unusual approaches. Worldwide cities are now more crowded than ever and more people are living inside high-rise buildings which also contributes to the problem. And yet, the available fire-fighting technologies have not appreciably changed over the years and are known to be inadequate in many ways. There is a demanding need for improved fire extinguishing processes.
One most common process for extinguishing fires is to pour water over a burning object. The basic scientific principle involved in extinguishing fire with water is to reduce a temperature of the burning object as each combustible material has its unique flammability temperature. A flame can be extinguished if the temperature of the burning object is reduced below a threshold temperature by wetting and cooling the burning object with water. However, the flame can resume when the water is evaporated and the object is again raised above this flammability threshold temperature. There are many materials, such as plastics, that are not water absorbent and that combust at very high temperatures or that combust in vapor form; water has very limited usefulness in extinguishing a fire of such materials.
Current water-based fire fighting processes also have shortcomings because of the delivery method. As a fluid, water flows down due to gravity such that its contact time with materials in a vertical, flowing downward, and inclined position is usually very short unless the spray is continuously applied over a period of time. The water spray is also often not powerful enough to travel a long distance, to reach a considerable height, or to break through common barriers such as windows, doors, roofs, and walls. In many cases, most of the water flows downward and is wasted. A good example is forest and bush fires in which a long contact time between the water and the burning branches is literally impossible to maintain, except by rain. Extinguishing common house fires within a house can be troublesome because of difficulties with pouring water into a house interior and onto burning surfaces. Fire can exist between the exterior walls and the interior walls or on ceilings, where water cannot be easily delivered into such space and onto such surfaces. As a result, much of the water consumed in fighting house fires causes water damage to the extent that even if a house is saved it is frequently damaged beyond repair.
A fire which occurs in a high-rise building is also a difficult fire to extinguish because of the difficulty in reaching the fire with water. Common sprinkler systems can be ineffective for various reasons. Likewise, fire which occurs at locations where water is scarce, or where fire equipment cannot be transported to the site, can be a problem where effective portable fire extinguishing equipment is unavailable. There are many other examples of ineffective currently available water-based fire fighting processes. Fires on oil storage tanks and on oceangoing oil tankers are very difficult to extinguish with conventional water processes. Airplane fires are another example of difficult fires to extinguish because of the presence of jet fuels and the large quantity of plastics materials. In some unusual cases, the water consumed in fighting fire can result in very severe environmental damage if it is not properly contained, as evidenced years ago in a fire that occurred in a chemical plant in Switzerland, in which the fire fighting water dissolved a large quantity of toxic chemicals and then flowed into the Rhine River and severely impacted the ecosystem of the Rhine River.
Since water is ineffective against certain types of fire and under certain conditions, more effective fire retardants have been developed and made available in various forms and packages over the years. These fire retardants, when released from their containers, can be in the form of a powder, a foam, or a liquid. They function in different ways and therefore should be used differently. Some produce inert gas such as carbon dioxide and nitrogen when they are heated, thus suffocating the fire; examples include sodium bicarbonate and azodicarbonamide. Others produce vapors that act as diluent and heat sinker to combusting gases or as a free radical trap that stops or slows flame propagation; examples include halogenated flame retardants. Still other fire retardants function on solid phase by forming a protective layer on combusting substances to inhibit heat transfer; examples include many phosphorous compounds. Then there are many common materials that are very effective fire retardant when they are spread over a burning object by isolating the burning object from the ambient air; examples include many earth minerals such as clay, alumina, and sand. These earth minerals are particularly effective when they are wet and impervious. There are also materials that are very absorbent to water and can swell to form a gel that can be very useful for extinguishing fires by acting as a wet blanket; examples include polyacrylamide polymers and copolymers, and some natural gums. All these materials have some very useful features that can be used to fight fires.
Unfortunately, the currently available processes involving the use of various fire retardants have a common shortcoming, namely poor delivery distance, accuracy, and coverage. For example, powders and foams are very light and they cannot be pumped easily or blown in air over a distance with any accuracy. Once delivered, powder and foam may have difficulty remaining on top of a burning object. For example, powder fire retardants are currently used to fight forest fires and are dropped from an airplane, with questionable effectiveness. Hand-operated fire extinguishers are effective only on small fires and in confined space because of limited delivery distance and light weight characteristics of the retardants. Sand is a good fire retardant, but there is no good way to throw sand over a distance. The currently available fire extinguishing processes based on fire retardants are also not powerful enough for breaking through barriers to reach interior fires. For example, the current practice of fighting ship fires is to spray water on the ship until it is virtually sunk. Therefore, to take advantage of the positive features of available fire retardants requires a more effective retardant delivery method. Further, a synergistic approach must be adopted to combine one or more materials to fight fires. For example, water can be used in conjunction with another fire retardant to create a slurry that can smear and stick to burning surfaces like a wet blanket rather than merely touch it which then flows downward.
One object of this invention is to provide an improved fire extinguishing process that combines the positive features of water and selected fire retardants with other suitable materials and devices to form a combination that can more effectively fight various types of fire, under a wide range of conditions.
Another object of this invention is to provide a process and apparatus that are useful for performing many other work tasks.
Another object of this invention is to provide an improved process and apparatus for extinguishing fire of many types.
Another object of this invention is to provide a process that uses a high-speed pulsed waterjet or other fluid jet to extinguish fires either by the fluid jet alone or in combination with selected fire retardants in various forms.
Another object of this invention is to provide an instant on-off valve useful in many fluid jet processes.
Still another object of this invention is to incorporate other selected materials or devices into the process to assist delivery of pulsed fluid jets and/or selected fire retardants and/or other materials that are useful in many other applications.
The process of this invention uses pressurization of a selected system fluid by a suitable pump or a source of compressed gas that is used to pressurize a system fluid inside a cylinder. The pressurized fluid is transported with a tube or hose into one or more energy storage devices in the form of a spring-powered or a gas-powered accumulator. The system fluid is stored inside an energy accumulator fluid chamber to a prescribed volume. The stored system fluid is ejected or discharged through one or more suitable instant on-off valves and nozzles to generate high-speed fluid jets on demand, and directing and delivering the fluid jet to a target. The selected system fluid can be water or other fluids, such as a pure liquid, an emulsion, a slurry, or a soft gel. The pump can be large or small, low pressure or high pressure, depending on the desired characteristics of the fluid jet. The pulsed fluid jet of this invention can be generated at a wide range of pressures, power input, frequency, and pulse durations by operating the energy accumulators and the on-off valves. The system equipment involved can be large and heavy, which of ten require mounting on a suitable chassis or carriage, or can be very portable that can be carried by a person, such as on a backpack. There can be multiple energy accumulators to a single pump, multiple on-off valves to a single energy accumulator, or multiple nozzles to a single on-off valve. The on-off valve used in this process is one important part of this invention. The nozzles on this process can be a simple fluid jet nozzle commonly used in water jetting applications or a compound nozzle that has components for introducing other substances into the fluid jet or to assist a fluid jet, such as during flight in air. The nozzles of the process of this invention may also be attached with a source of optical light or laser light, for the purpose of illuminating the fluid jet.
The process of this invention also uses a fluid jet to carry selected additives to assist extinguishing fire or doing other work. The additives can be added to the fluid prior to pressurization to form a mixture, a colloid, a soft gel, or a slurry and then introduced into the system equipment and eventually discharged or ejected out of the nozzle as a pulsed fluid jet. In an alternative embodiment of this invention, selected additives are introduced into the pulsed fluid jet in the nozzle chamber by utilizing a venturi effect generated by the fluid jet, or by loading the additives into the nozzle chamber by gravity, by pressure, or by other suitable mechanical means. The additives are preferably formed as a liquid, a slurry, a soft gel, a powder, or pellets that can be introduced into the fluid jet nozzle, preferably in a simple manner. In one embodiment of the pulsed fluid jet process of this invention, selected additives are time loaded into a nozzle chamber prior to issuing a pulsed jet. The fluid jet passes through the nozzle chamber and carries additives through a secondary nozzle to be shaped into a high-speed slurry jet. Thus, in this process there is proper energy transfer from the fluid jet to the additives. Such energy transfer is not proper or possible with a setup that uses continuous fluid jet. In fighting fires, the fluid jet of this invention can act as a carrier for the additives.
The process of this invention also use a special-effect device that is introduced into or onto the nozzle and ejected with or propelled by the pulsed fluid jet, for various suitable purposes. This device may be in the form of a ball, a bullet, a cap, a capsule, a cartridge, a shell, a tube or the like. This added device can be for shielding the pulsed fluid jet and/or the additives against the air during flight so that the fluid jet can travel much further, particularly with less dispersion. The added device can be packed with fire retardants and can be used or manufactured with fire retardants, to play an active role in fighting fires when propelled into a fire by the pulsed fluid jet. The added device of this invention can also be used as a piercing tool, allowing the retardants to be delivered into a closed space, such as a house, by breaking through barriers. The added device of this invention can also be installed with a valve or another material-releasing mechanism to perform special effects, such as releasing fire retardants to cover a large area.
The pulsed fluid jet of this invention is an ideal tool for propelling fire retardants because of the following reasons.
Water or another suitable liquid alone is or can be made to be an effective fire retardant. For example, carbon tetrachloride is a non-conductive and non-flammable liquid that can be useful in fighting an electrical fire, particularly when it is used in conjunction with conventional Halon powder. Water can be converted into a sticky soft gel with various additives such that it will smear a surface instead of flowing quickly down the surface.
Water or another suitable liquid can be pressurized to a high level and ejected or discharged through a nozzle to generate a pulsed jet that can be very fast and can pack considerable power which is particularly suitable for carrying additives. Air or gases, in contrast, cannot be used to generate a very fast jet and cannot be readily pressurized, due to its compressible nature.
Liquid having a specific gravity not too different from that of solid fire retardants allows a pulsed liquid jet to transfer energy more effectively to additives when compared to an air jet or a gas jet.
Waters and other selected liquid jets do not generate much heat in repeated operations and thus do not interfere with fire retardants. Explosives, on the other hand, cannot be used to propel many fire retardants due to the heat generated inside a tube, and the heat can set off the fire retardants.
The process of this invention also includes the use of a light source, such as laser light or other suitable optical lights, to illuminate a pulsed fluid jet issued from the nozzle for various purposes.
The process of this invention can be used also for delivering selected materials for other purposes, such as agricultural, environmental, and construction applications. For example, seeds, fertilizers, insecticides, and bioremediation reagents can be delivered effectively with the process and equipment of this invention. Soil stabilization materials can be blown over or injected into earth embankment, slopes, and ground with the process of this invention. Even seedlings can be propelled by pulsed fluid jet according to the process of this invention, and planted over a distance by using special capsules.